Introducing LibrePilot



If you know a little bit of OpenPilot history you understand it was more about when, not “if”.  After a little less than 4 years of contributions to the OpenPilot project it was time to part.

Just to give a bit of context, I started with OP at the beginning of 2012, working at the early stage of the revolution firmware and hardware development. I mostly took care of the bare metal firmware side, sensors and peripherals interfaces, porting the code to various targets (i.e. STM32 F0 for GPS V9, STM32F411 for nano Nano). I‘ve also participated in hardware development/validation and testing since the initial Revolution prototypes (not the small officially sold, but the previous bigger brother ) . I’ve worked at flight performances improvement with mini quads for CC3D/Revo (the thing that, together with the acro+ develiped by Eric/CorvusCorax,  made CC3D so popular in the 250 class racers) , implemented OneShot, notification smart leds support, a new sensor framework implementation and several other things.

Later I’ll have to write some detailed chronological history of the awful situations,  the falsification and everything else happened in the last 1 and 1/2 months that brought me, most of the development team and several key members to build a new project (LibrePilot) from the roots of OpenPilot.

One question that i have been asked several time is: wouldn’t be better to join to an existing project, like TauLabs?

This was actually one of the possibilities, the fact is that we are already a solid, very well proven team and this may have caused “integration” issues.

But the intentions are to collaborate with other projects, especially TauLabs. Probably one of the best (long term) bets for both projects is to converge to a single codebase that takes the best of both worlds. Unfortunately it is a quite demanding task as in the last couple of years they have diverged a lot, but surely it will worth the effort, both in term of features/quality than in term of critical mass of users and development team.


Foldable quad for ROS integration experiments

I’m shortly going to work integrating the OpenPilot telemetry with ROS.

Main (long term) focus is indoor positioning and navigation.

This is a quick mockup of the craft that will be used. Plates are going to be rebuilt to better host everything


The reference platform  is made by

  • OpenPilot Revolution flight controller;
  • OpenPilot GPSV9 with integrated magnetometer;
  • Control link using Revolution on board OPLink;
  • ODroid U3 sbc hosting Ubuntu server 14.04 with ROS Indigo;
  • WIFI card TL-WN722N (that uses an external antenna connected with a RPSMA);
  • USB Web Cam, initially used for optical flow.
  • Telemetry link using WIFI connection;
  • Connection between Revolution and Odroid using USB.
  • Sonar sensor for precise agl measurement

DSC_0554 DSC_0555 DSC_0557 DSC_0559 P1020406 P1020407 P1020408

Mini Revo foldable H frame

Here are the drawings for a mini-H I built some time ago.

it can be easily folded to be put in a backpack.

The design was built using the following materials:

Main center frame assembly

  • n° 14 M2x16 hex socket bolts
  • n° 12 M2 nuts
  • n° 8 M2 self locking (nylock) nuts
  • n° 14 M2 washers

 Arm assembly

  • 4 M3x16 Stainless steel bolts
  • 4 M3 self locking (nylock) nuts
  • 8 M3 washers
  • 8 M2x16 (but should be shorter) bolts for motor mounts
  • 8 M2 self locking (nylock) bolts
  • 16 M2 washers

Board mounting

  • various M3 nylon spacers/bolt/nut and M3 polycarbonate screws

Power stage

  • 2730 1300Kw blue wonder from giantshark
  • HK blueseries 12A Esc flashed with simonk firmware,
  • ARDrone propeller set modified cutting the various pins on the back and enlarging the hole to 3mm.

To attach the props i removed the prop saver, inserted the prop on the axle and tied using some thin multifilar fishing line and that works great.

I use it both with 2s 1300 for indoor testing or 3S 2200 for outdoor fun.

Refer to this thread for further information and for asking questions: link to OpenPilot forum

Link to design files

Rebuilt mini swift

After a huge amount of crashes with my mini swift, i eventually decided to rebuild it creating an hatch in the top where I can put a CopterControl and, in a near future, GPS and PipXtreme on it.
The little thingy is not really light as I put a hxt 2730 motor (25gr motor only) with a 2S 1000mAh LiPo. The total AUW is around 225gr.

CNC’d case for op revo board

Here is a new case for the upcoming Revolution board from the awesome OpenPilot project.
The case is built by two shells 5mm thick made by polystyrene glass.
It is milled with 3mm two flute endmill at 900mm/min feeding rate and 1.5-2mm depth. You also need to cool down the mill from time to time to prevent the polystyrene from melting. Just spray some water on the mill while it’s cutting.




Mini VTail quad

Hi guys.
I have problem with my bigger quad (one esc does weird things raising throttle) so i cannot fly for now.
So It was time (while waiting for my holidays) to finish a mini vtail quad I had in mind for a lot of time.
I is basically built around some 4mm carbon fiber tubing and some kite rubber joints.
I used a 4mm kit and a 6mm kit. The 6mm provied the joint used to hold the four motors while the 4mm was used for the remaining joints used to build the structure.

Here is the base frame composed of carbon tubing and a little glass fiber rectangle.
The rectangle was epox’ed to the tubes after it was tied using some  wire. In the rectangle there are four rows of holes used to let the wire passing through it.

Here is better shown how it is tied.

After the base frame was ready I started to put the electronic on it. Here there are two escs, a simple ditribution board and the CopterControl that will power the Vquad.

In this pictures it is almost complete. all the wirings were done and all is ready for testing motors.

Here is another pictures with propellers. all is wired  (There is also the Bluetooth module i used to configure the CopterControl and test motors  without the need for the usb cable)

Now the last  missing piece is the adapter (a simple 3.3V power regulator) needed to attach a Spektrum satellite receiver to the CopterControl. I hope to finish it tomorrow to be able to do  some flying tests with the newborn VQuad 😉


I forgot to put the specs of the quad as is now:

Motors: 4 hxt 2730 rewound as 10turns wye for the two in front (with gws 8×4 propellers) and 10turns delta for the two rear motors (with 5.5×4.5 APC propellers)

ESC: 4 12A hobbyking blueseries

Tubing is 4mm carbon fiber tube (used for kites)

Joints are from 4mm and 6mm kite joint kits

Battery is a 2s 1000mah 25c Turnigy nanotech

Orange Sat Receiver for Spektrum

The weight is a little less than 300gr with battery.


Update: Here is a video of the first test done: